- Established 1982 -

HOME: www.hiltonpond.org

1-28 February 2017

Installment #651---Visitor #AmazingCounters.com

Subscribe for free to our award-winning nature newsletter

(Back to Preceding Week; on to Next Week)

Our next two
Operation RubyThroat
Tropical Hummingbird Expeditions to

Costa Rica

11-19 Nov 2017 & 20-28-Jan 2018

Come be part of a real
citizen science project

(Blue-crowned Motmot above right)

All text, maps, charts & photos © Hilton Pond Center


It should not be a surprise to folks who know birds that our most common avian visitors to Hilton Pond Center are species that hang out in flocks AND that just happen to like food we make available in various kinds of feeders. Our top three flocking species are, in order of number banded: American Goldfinch (late winter adult male, above), House Finch, and Purple Finch. If it weren't for all those Ruby-throated Hummingbirds that lap up gallons of sugar water, a fourth finch species--Pine Siskin--would be in the #4 position.

All text, maps, charts & photos © Hilton Pond Center

(Click on chart above for a larger version in a new browser window)

We offer bird seed and suet year-round that attract a smattering of American Goldfinches (AMGO) and House Finches during the breeding season. Then, as summer turns to fall the finches start trickling in--sometimes waterfalling--until reaching highest numbers in January and early February. Although some years there are few Purple Finches and absolutely no Pine Siskins, typically we can depend on AMGO to keep us busy placing sunflower seed in two over-sized tube feeders. Annually over our 36 years of work at the Center we've banded an average of 295 goldfinches (see chart above), with a record-shattering 838 back in 2007. And, as the dotted red trend line on our chart reveals, we've seen a significant increase in banded AMGO since 1982. (We suspect the 220 goldfinches banded in 2017 through February will have helped us reach at least the 400 mark by year's end.)

All text, maps, charts & photos © Hilton Pond Center

Winter American Goldfinches at Hilton Pond Center look very different from those we band April through October, primarily because they're in non-breeding plumage. Adult males (above) may have a hint of bright yellow, but their body plumage is drab and they show only a hint of the black forehead and crown that are part of their breeding attire. Sometimes AMGO can be identified as adult male because of a bright yellow bend in the wing, visible in the image above. (NOTE: Despite what you may read in field guides this is NOT the bird's shoulder, but its wrist.) In winter the bill is colored differently in both males and females--brownish black instead of the carrot-orange mandibles of summer. (Also see photo of winter male at top of page.) One thing that does not change in males, however, is the color of their jet-black wing feathers.

All text, maps, charts & photos © Hilton Pond Center

Winter males do resemble less brightly colored females, but the female's wrist is never yellow. Furthermore, a female's wings (above) are never jet black and vary from brownish black to a subdued black that contrasts less obviously with the white tips of secondary coverts; to be honest, wing color is sometimes hard to discern from a distance, but comparing overall appearance of goldfinches at a feeder usually allows you to differentiate sexes.

All text, maps, charts & photos © Hilton Pond Center

When a male AMGO fledges his wrist lacks yellow feathers; instead it is a mix of black and olive feathers as shown in the photo just above. It takes a male two years to acquire his yellow wrist, so if seen in February 2017 a bright-wristed adult male must have hatched in 2015 or earlier and is called after-second-year.

All text, maps, charts & photos © Hilton Pond Center

Even though their wrists are drab young males still have jet black wing feathers (above). This image also shows how recently fledged goldfinches of either sex may have brownish wing bars instead of white.

All text, maps, charts & photos © Hilton Pond Center

Ageing young male American Goldfinches is relatively easy--especially in-the-hand when you can look closely for the absence of a yellow wrist. As noted, it may even be possible to determine adult males at your feeder if you can see a bright wrist. Young females (above) can be especially drab, but conclusively ageing them can be a more difficult matter.

All text, maps, charts & photos © Hilton Pond Center

For a bird bander, one of the best ways to age female American Goldfinches is to look at the rectrices (tail feathers). If the tips are acute (pointed), as above, the bird is a youngster; i.e., a hatch-year individual through 31 December, or an after-hatch-year beginning 1 January. Tail feathers on younger birds often show more wear.

All text, maps, charts & photos © Hilton Pond Center

Instead of bearing pointed rectrices an adult (after-second-year) AMGO typically will have tail tips that are broadly rounded (above) and show minimal wear. (NOTE: As indicated by strong white edging on individual feathers, both photos above are actually of male goldfinches. Although females do not show this degree of white edging, the images still nicely demonstrate the pointed vs. rounded nature of rectrices in "young" and "old" AMGO.)

All text, maps, charts & photos © Hilton Pond Center

And just another word about bill color in American Goldfinches. The adult female in the image above has dark mandibles that are typical of both male and female AMGO in winter. Bird bills are comprised of keratin--that same hard material of which human fingernails and horse hooves are made. Since keratin is non-living, one might wonder how a goldfinch's bill can change to bright orange during the breeding season. The answer is this: Keratin makes up only the bill's hard outer sheath, beneath which lies living skin tissue with active blood vessels.

All text, maps, charts & photos © Hilton Pond Center

With the arrival of spring, a goldfinch's entire metabolism changes. Dormant gonads re-enlarge, releasing hormones that cause the bird to lay down yellow pigment in new feathers that, in turn, replace the drab plumage of winter. Hormones likewise direct cells in the bird's living mandibular tissue to deposit yellow and red pigments that apparently mix to make the bill orange. The early spring male in the photo above--breeding-bright and with a black forehead--still has some drab winter nape feathers and his bill has not yet changed over to being fully orange.

Although lots of birds go through spring molt, the process seems more dramatic among American Goldfinches--especially males. (Quick change artists, indeed. See "calico" male below right.) A question we've always had is why goldfinches should even acquire breeding plumage so early in the year. After all, American Goldfinches are among the very last birds to build nests, lay eggs, and fledge young in late summer and early fall, so it seems being an "unnecessarily bright" non-breeding bird against the spring landscape would make AMGO much more visble to potential predators. Thus, there must be something else going on that makes an early molt so advantageous. Perhaps it's important for American Goldfinches to appeal early to prospective mates, or maybe it's something else entirely. We welcome your thoughts about what might be happening at INFO.

Incidentally, American Goldfinches--like other birds--don't make all that yellow, red, and orange pigment on their own. Instead they rely on food as the source for these chemical pigments. Plants CAN manufacture colorful xanthophyll and carotene--often sequestered in their fruits--so when you hang a thistle sock (above) or a tube feeder full of sunflower seeds you're providing plant pigments your American Goldfinches need to to become "gold." (Theoretically, if you could raise an AMGO on food that didn't contain any plant pigments, he would turn out to be a grayfinch instead. Even insects the goldfinch eat get their yellow and red pigments from plants THEY feed on.)

All text, maps, charts & photos © Hilton Pond Center
Photo above from public domain

We recently saw aan on-line photo of an inexpensive three-tube finch feeder with feeding spaces purported for up to 24 American Goldfinches. (Can you age and sex all the AMGO in the advertising photo above?) Always eager to try out a new feeder style, we ordered one and upon receipt filled it with what one dealer calls a "deluxe winter finch mix" (This mix contains pigment-rich nyger thistle, white millet, canary seed, finch millet and sunflower chips, although there is some indication goldfinches ignore white millet and canary seed, dropping the latter where ground-feeding sparrows will eat it. One suggestion is to make your own "goldfinch mix" of nyger, sunflower chips, and perhaps finch millet if you can find it.) American Goldfinches were already on the wane at Hilton Pond Center by the time we hung the feeder, so the best we could do was a "mere" 12 at once! We look forward to next fall's arrival of "drab winter goldfinches" and the opportunity to practice ageing and sexing these abundant little birds on our new triple-tube feeder. (P.S. All the AMGO on the triple tube feeder above appear to be adult males.)

All text, maps, charts & photos © Hilton Pond Center

All text, maps, charts & photos © Hilton Pond Center

Seventh-year male American Goldfinch (above) wearing
a well-worn Size 0 band

Don't forget to scroll down for Nature Notes & Photos,
plus lists of all birds banded or recaptured during the period.

Payable to: funding@hiltonpond.org

Checks can be sent to Hilton Pond Center at:
1432 DeVinney Road
York SC 29745

All contributions are tax-deductible on your
current-year income tax form

See list of recent supporters below

"This Week at Hilton Pond" is written and photographed by Bill Hilton Jr., executive director of Hilton Pond Center for Piedmont Natural History

Please refer "This Week at Hilton Pond" to others by clicking on this button:

Follow us on Twitter:


Comments or questions about this week's installment? Send an E-mail to INFO. (Be sure to scroll down for a tally of birds banded/recaptured during the period, plus other nature notes.)

Click for York, South Carolina Forecast
Click on image at right for live Web cam of Hilton Pond,
plus daily weather summary

Transmission of weather data from Hilton Pond Center via WeatherSnoop for Mac.

You may wish to consult our Index of all nature topics covered since
February 2000, or use our on-line
Hilton Pond Search Engine:

For your very own on-line subscription to "This Week at Hilton Pond,"
just click on the image above. It's guaranteed fat-free!

Thanks to the following fine folks for recent gifts in support of Hilton Pond Center for Piedmont Natural History and/or Operation RubyThroat: The Hummingbird Project. Your tax-deductible contributions allow us, among other things, to continue writing, photographing, and sharing "This Week at Hilton Pond" with students, teachers, and the general public. Please see Support or scroll below if you'd like to make a gift of your own.

We're pleased folks are thinking about the work of the Center and making donations. Those listed below made contributions received during the period. Please join them if you can in coming weeks.

Gifts can be made via PayPal (funding@hiltonpond.org); credit card via Network for Good (see link below); or personal check (c/o Hilton Pond Center, 1432 DeVinney Road, York SC 29745).

  • Kenneth Baerwalde (repeat donor)
  • Alexis Dandretta (via PayPal; long-time supporter and alumna of an Operation RubyThroat hummingbird expedition to Costa Rica)

If you enjoy "This Week at Hilton Pond," please help support
Hilton Pond Center for Piedmont Natural History.
It's painless, and YOU can make a difference!

(Just CLICK on a logo below or send a check if you like; see Support for address.)

Make credit card donations
on-line via
Network for Good:
Use your PayPal account
to make direct donations:
If you like shopping on-line please become a member of iGive, through which 1,800+ on-line stores from Amazon to Lands' End and even iTunes donate a percentage of your purchase price to support Hilton Pond Center. ..Every new member who registers with iGive and makes a purchase through them earns an ADDITIONAL $5 for the Center. You can even do Web searches through iGive and earn a penny per search--sometimes TWO--for the cause! Please enroll by going to the iGive Web site. It's a painless, important way for YOU to support our on-going work in conservation, education, and research. Add the iGive Toolbar to your browser and register Operation RubyThroat as your preferred charity to make it even easier to help Hilton Pond Center when you shop.

The Piedmont Naturalist--Vol. 1--1986 (Hilton Pond Press) is an award-winning collection of newspaper columns that first appeared in The Herald in Rock Hill SC. Optimized for tablets such as iPad and Kindle, electronic downloads of the now out-of-print volume are available by clicking on the links below. The digital version includes pen-and-ink drawings from the original edition--plus lots of new color photos. All sales go
to support the work of
Hilton Pond Center.

1-28 February 2017

American Goldfinch--
Chipping Sparrow--16
Carolina Chickadee--1
Pine Warbler--1
Northern Cardinal--1
Purple Finch--142

House Finch--26
White-throated Sparrow--1
Eastern Tufted Titmouse--2
Eastern Bluebird--1

* = new banded species for 2017

16 species
403 individuals

16 species (35-yr. avg. = 63.9)

339 individuals
(35-yr. avg. =

(Banding began 28 June 1982; since then 171 species have been observed on or over the property.)
126 species banded
65,463 individuals banded

(with original banding date, sex, and current age):
American Goldfinch (7)
03/23/14--5th year female
02/21/15--4th year male
03/07/15--after 4th year male

01/01/16--after 3rd year female

01/09/16--3rd year female
01/09/16--3rd year female (two birds)
01/20/16--3rd year male

Carolina Chickadee (1)
08/21/16--2nd year unknown

Chipping Sparrow (3)
02/04/14--after 4th year unknown
01/01/16--after 3rd year unknown
03/21/16--3rd year unknown

Eastern Tufted Titmouse (2)
06/02/16--2nd year female
06/15/16--2nd year unknown

Purple Finch (6)
03/13/09--10th year male

01/13/15--4th year female
02/18/15--4th year male
03/03/15--after 4th year male
03/18/15--4th year male

03/02/16--3rd year female

House Finch (14)
05/10/16--2nd year male
05/16/16--2nd year male
05/25/16--2nd year male
05/31/16--2nd year female
06/12/16--2nd year male
06/12/16--2nd year male (two birds)
06/13/16--2nd year male
06/24/16--2nd year female
06/27/16--2nd year male
07/08/16--2nd year female
07/18/16--2nd year male
08/09/16--2nd year male
11/30/16--after hatch year female
12/15/16--after hatch year female

--American Goldfinches finally showed up in good numbers at Hilton Pond Center in early Feb 2017. On consecutive days during first two weeks we banded 20, 8, 6, 32, 35 & 17 individuals. Even so, we are behind on AMGO bandings for a typical winter, possibly because weather has been so mild and birds are feeding on natural foods rather than coming to our seed-baited traps. It's also likely some facultative (non-obligatory) migrants have yet to move south because weather has been relatively mild to our north.

--We also had some excellent returns during February for birds banded in previous years at the Center (see list lower left). Most notable was a Purple Finch banded as unknown age and sex on 13 Mar 2009. Since he bore red plumage this year, that means he is a male that must have hatched in 2009--a TENTH year bird. This ties our record for oldest known bird of any species at Hilton Pond.

--Since they do not breed in the Carolina Piedmont, those five Purple Finches on the return list February all made numerous migratory round trips before being encountered again at Hilton Pond. In contrast, at least 12--and probably all--the 14 House Finches listed were banded as young birds that fledged locally and likely never left the area. The same would be true of the Eastern Tufted Titmice and Carolina Chickadee.

--As of 28 Feb the Center's 2017 Yard List stood at 40--about 23% of the 171 avian species encountered locally since 1982. (If you're not keeping a yard list for your own property we encourage you to do so, and to report sightings via eBird.) New species this week: Great Horned Owl & Barred Owl (both heard), Pine Warbler (banded) & Common Grackle.

--The immediate past installment of "This Week at Hilton Pond" was about wild swings in temperatures during January 2017 and some ensuing nature observations. It is archived and always available on the Center's Web site as Installment #650.

All text & photos © Hilton Pond Center

Oct 15 to Mar 15:
East of the Rockies please report your sightings of
Vagrant & Winter Hummingbirds

(immature male Rufous Hummingbird at right)

(Back to Preceding Week; on to Next Week)

Back to "This Week at Hilton Pond" Main

Current Weather Conditions at Hilton Pond Center

The Center's backyard Web cam at Weather Underground

Hilton Pond Center for Piedmont Natural History is a non-profit research, conservation & education organization in York, South Carolina USA; phone (803) 684-5852. Directed by Dr. Bill Hilton Jr., aka "The Piedmont Naturalist," it is parent organization for Operation RubyThroat. Web site contents--including text and photos--may NOT be duplicated, modified, or used in any way except with express written permission of Hilton Pond Center. All rights reserved worldwide. To request permission for use or for further assistance, please contact Webmaster.